JPH06100206B2 - New Matte Actuator - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic actuator that imparts an axial motion to a driven member by using the energy of a pressurized fluid.

(Prior Art) By introducing a pressurized fluid into the internal cavity of the tubular body,
An air bag type pneumatic actuator that expands in the radial direction and produces a contracting force in the longitudinal direction is lighter in weight than the reciprocating actuator that uses a hydraulic cylinder or an electric motor, and due to leakage of hydraulic oil. It has many excellent features such as no environmental pollution and no problems such as fire caused by sparks.

As such an actuator, for example, the one shown in FIG. 5 (a) is disclosed in Japanese Patent Publication No. 52-40378. Reference numeral 1 is a tubular body, 2 is a braided reinforcing structure on the outer periphery thereof, and 3 is a closing member at both ends. The tubular body 1 is made of rubber or a rubber-like elastic material or a material equivalent thereto in consideration of air impermeability, and the braided reinforcing structure 2 is used for the braided structure when the tubular body 1 is expanded to the maximum diameter by the internal pressure filling. It has a braided structure such that the angle θ reaches a so-called static angle (54 ° 44 ').

Such an actuator A, when a control pressure is applied to the closed space 6 of the tubular body 1 via a fitting 5 attached to at least one connection hole 4 of the closing member, expands the braid angle of the braided reinforcing structure, that is, pantograph movement. The swelling of the tubular body 1 and the contraction in the axial direction resulting therefrom, that is, the distance between the connecting pin holes 7 formed in the closing member is reduced. Reference numeral 8 indicates the crimping caps at both ends.

In order to give a desired amount of reciprocating motion to a driven member using this known actuator, one ends of two actuators are connected to each other via a driven member 9 as shown in FIG. 5 (b). And connect each other end to the fixed wall,
Adjust the application of control pressure to each actuator,
It was giving the desired amount of reciprocating motion.

(Problems to be Solved by the Invention) This drive device expands the tubular body by introducing compressed air into the closed space 6 of the tubular body 1 to perform the work, so that the energy of the compressed air can be effectively used. In addition, there is no problem of backlash in a drive device in which an electric motor and a ball screw are combined, and there is no problem of positioning accuracy due to the compressibility of air when a pneumatic cylinder is used. However, since air is used as the working medium, the output is comparatively smaller than that of an actuator having a cylinder structure, and at the time of operation, air corresponding to the volume defined by the tubular body must be supplied to and exhausted from the tubular body. However, there is a problem that the air consumption as the working medium is large.

It is an object of the present invention to provide a pneumatic actuator that solves the above-mentioned problems without impairing the advantages of air bag type actuators.

(Means for Solving the Problem) The pneumatic actuator of the present invention is a braided reinforcement of organic or inorganic high-strength fibers, which entirely covers a tubular body made of rubber or a rubber-like elastic material. A structure is provided, and both ends of the tubular body and the braided reinforcing structure are sealed and joined by a closing member to define a closed space inside the tubular body, and a guide is provided between the closing members in the closed space. An inner peripheral surface of the tubular body is provided with a guide ring which is provided so as to extend and which is fitted to the outer periphery of the guide member so as to be displaceable in the axial direction thereof and which divides the closed space into two inner cavities. And a driven member for sandwiching the tubular body and the braided reinforcement structure, which is integrally displaceable with the guide ring, is provided outside the tubular body and the braided reinforcement structure at a position radially outward of the guide ring. , For each closure member, A supply / discharge port for supplying / discharging a pressurized fluid is provided in each internal cavity.

Here, preferably, the guide ring and the driven member are integrally formed.

Further, preferably, in addition to the above, detection means for detecting the relative displacement amount of the guide ring with respect to the guide member, and display means for displaying the relative displacement amount corresponding to the output signal from the detection means are provided.

(Operation) In order to operate this actuator, in a pneumatic actuator held at a preliminarily set initial pressure, one of the internal cavities is operated as an example of a pressurized fluid under the effect of each supply / discharge port. Compressed air is supplied and compressed air is discharged from the other internal cavity. Therefore, the braided reinforcing structure portion on the side supplied with the compressed air performs pantograph motion, and the tubular body portion associated with the braided reinforcing structure portion expands in diameter to further generate a contracting force in the axial direction. On the other hand, in the braided reinforcement structure portion on the side where the compressed air is discharged, the braid angle is reduced with a decrease in the internal pressure, so that the related tubular body portion is reduced in diameter by the restoring force of the tubular body itself, and the contraction force is reduced. Along with the decrease of, the axial extension. Therefore, the guide ring fixed to the inner peripheral surface of the tubular body moves along the guide member toward the closing member on the side where the compressed air is introduced, to the equilibrium position corresponding to the pressure difference in each internal cavity. As a result, the driven member fixed to the guide member by, for example, screwing also moves to the equilibrium position corresponding to the pressure difference in the inner cavities. That is, it is possible to displace the driven member to a desired position by appropriately adjusting the pressure difference between the inner cavities. In order to move the driven member to the original position or in the direction of the other closing member, compressed air is introduced into the internal cavity associated with the closing member and air as the working medium is discharged from the other internal cavity. Just do it.

By the way, with this pneumatic actuator,
Since the guide member is provided so as to extend between the closing members, the volume of air consumed can be reduced by the volume of the guide member to reduce the pressure source capacity of the compressor and the like, and the braided reinforcing structure. The contraction force per pitch can be greatly increased as compared with the prior art, as will be apparent from the later detailed description.

Here, when the guide ring and the driven member are integrally formed, the assembly of the actuator can be facilitated as compared with the case where the respective guide rings and the driven member are individually attached at predetermined positions.

In addition, when the means for detecting the relative displacement of the guide ring with respect to the guide member and the means for displaying the detection result are provided, it is possible to easily and quickly confirm the operating state, operating accuracy, etc. of the actuator, and to confirm the confirmation. Feedback control based on the results can be made extremely easy.

(Example) The pneumatic actuator of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a preferred embodiment of the pneumatic actuator according to the present invention, showing the actuator in the initial setting state under the application of the pressurized fluid. In addition,
In the figure, the same parts as those shown in FIG. 5 are indicated by the same numbers.

That is, 1 is a tubular body, 2 is disposed on the outside thereof, and a braided reinforcing structure that covers it almost entirely, 3a, 3b,
Respective closing members for sealing and joining the openings of the tubular body 1 and the braided reinforcing structure 2, 4a and 4b are connecting holes provided in the closing members 3a and 3b, 5 is a fitting attached to these connecting holes, and 7 is The continuous pin holes, 8 formed in each closure member, respectively, indicate the crimp caps which, in cooperation with the closure members 3a, 3b, contribute to the respective sealing joints of the tubular body 1 and the braided reinforcing structure 2.

Here, in this actuator, a guide member 10 made of metal or synthetic resin having both ends fixed to the closing members 3a and 3b is provided so as to extend between the both closing members. Since the guide member 10 receives a contracting force in the axial direction when the actuator is operated, the size, shape, and material of the guide member 10 are appropriately selected according to the specifications of the actuator so that the guide member 10 does not bend easily at that time. And

A guide ring 11 is fitted on the outer periphery of the guide member 10. In this embodiment, the guide ring 11 is fixed to the inner peripheral surface of the tubular body 1 at the outer periphery by sealing with an adhesive and is defined by the tubular body 1 and the closing members 3a, 3b. The closed space is divided into two internal cavities 6a and 6b. The inner diameter of the guide ring 11 is determined so that it can move in parallel along the guide member 10 by applying a control pressure to the inner cavities 6a and 6b.

The driven member 9 located radially outward of the guide ring 11 is fixed using known fixing means, for example, screws (not shown), so that the tubular body 1 and the braided reinforcing structure 2 are secured.
Is clamped together with the guide ring so that the guide ring 11 and the driven member 9 integrally move in the axial direction of the guide member 10. In this embodiment, in order to prevent the tubular body 1 and the braided reinforcing structure 2 from being worn by the contact with the edge of the driven member 9 when the tubular body 1 is expanded, the same as the caulking cap 8 is used. Then, the edge is curved as indicated by reference numeral 12.

Next, the operation of the pneumatic actuator thus configured will be described with reference to FIG. 1 (b). However, the actuator is attached to a fixed wall shown by a chain double-dashed line in the figure by a connecting pin hole 7, and each fitting 5 is a pipe line including a control valve, and an operating pressure source (not shown) such as an air compressor. Be connected to.

Compressed air is discharged from one of the inner cavities 6a set to the initial set pressure through the communication hole 14a provided in the guide member 10 and the fitting 5. On the other hand, compressed air is supplied to the other internal cavity 6b set to the initial set pressure through the fitting 5 and the communication hole 14b provided in the guide member 10.
Then, the braided reinforcement structure on the side that supplied compressed air
Performing pantograph movement, the tubular body portion expands and contracts to further generate contraction force. On the other hand, the braid reinforcing structure portion on the side from which the compressed air is discharged has a smaller braid angle, and the tubular body portion has its diameter reduced by its own restoring force and expanded in the axial direction with a decrease in the contracting force. Therefore, the guide ring 11 and the driven member 9 have a difference in contraction force of the tubular body part divided by the guide ring 11, that is, both inner cavities 6a, 6b.
1B to the equilibrium position corresponding to the difference in applied pressure in the direction indicated by arrow X in FIG.

At this time, the tubular body 1 expands substantially uniformly in the radial direction, so that the driven member 9 is in a state as if it was subjected to internal pressure. Therefore, the guide ring 11 fixed to the driven member 9 does not substantially come into sliding contact with the guide member 10 and X
Move in the direction. It is possible that compressed air may leak from the high-pressure internal cavity 6b to the low-pressure internal cavity 6a through the gap between the guide member 10 and the guide ring 11,
The amount of compressed air leaked based on the pressure difference between the internal cavities 6a and 6b is checked in advance, and the control valve of the pipe connected to the fitting is adjusted to compensate for the amount of leaked air, or a guide ring is used.
By providing a labyrinth seal on 11 or by combining these, the guide ring 11 can be moved with almost no influence of sliding resistance. Therefore, the driven member 9 can be accurately positioned.

By the way, in the actuator according to the present invention in which the outer diameter is 14 mm, the length is 400 mm, and the movable range of the driven member is 80 mm, the error is ± 1 μ.
Positioning with an accuracy of m was possible.

Next, the difference in contraction force between the pneumatic actuator of the present invention shown in FIG. 1 (a) and the known pneumatic actuator shown in FIG. 5 (a) will be described with reference to FIG. To do. Note that the inner diameter of the tubular body is D, the length of one pitch of the braided reinforcing structure is L, the braid angle is θ, the outer diameter of the guide member 10 is D ₁ , and the contracting force of the tubular body when the control pressure P is applied is Let F be the length L part.

The force acting in the length direction is calculated by considering the cross-sectional area of the tubular body, The force acting in the circumferential direction is DLP / 2, where T is the force acting on the braided reinforcing structure at this time, and considering the balance of the forces in the longitudinal direction. Considering the balance of forces in the circumferential direction, Tsinθ = DLP / 2 (2) From Fig. 2 (b) Ltanθ = Dπ (3) From equations (1), (2) and (3), T And erase L and If similar calculations are performed for the known actuator shown in FIG. As is clear from the equations (4) and (5), in the pneumatic actuator of the present invention, the contracting force per pitch of the braided reinforcing structure is larger than the known actuator by the cross-sectional area of the guide member 10. Applied control pressure, ie It becomes larger by the amount indicated by. In addition, the amount of compressed air applied corresponding to the volume occupied by the guide member can be reduced.

FIG. 3 shows another embodiment of the present invention. In this embodiment, two tubular bodies 1 each having one opening sealed and joined by a closing member and having an outer periphery reinforced by a braided reinforcing structure 2 are used, and the other opening is integrally formed with a guide ring. The formed driven members are sealed and bonded to form internal cavities 6a and 6b, respectively.

More specifically, the driven member main body 9a directly fitted to the guide member 10 is provided with a guide ring portion 11a projecting from its end face in the axial direction, and one side is provided around the projecting guide ring portion 11a. Of the two tubular bodies 1 whose openings are sealed and joined by the closing members 3a and 3b, the other openings of the tubular bodies 1 are fitted to each other, and the driven member main body 9a is positioned at the respective positions corresponding to the guide ring portions 11a. The caulking ring 15 is caulked and fixed, and the tubular body 1 and the braided reinforcing structure 2 are sandwiched, whereby the other opening of each tubular body 1 is sealed and joined.

The operation thereof is the same as that of the embodiment shown in FIG. 1 and therefore omitted. However, it is not necessary to fix the guide ring 11 at a predetermined position on the inner wall of the tubular body 1, which is advantageous in manufacturing.

Furthermore, another embodiment of the present invention shown in FIG.
The amount of relative displacement between the guide member 10 and the guide member 10 can be detected.

In this embodiment, the guide ring 11 is made of a magnetic material, and the guide member 10 is embedded with a coil consisting of a primary coil, a secondary coil, and a tertiary coil. Configure a dynamic transformer. The output from this differential transformer is connected to the display means 18 via the lead wire 17.
It is connected to the.

Therefore, if the guide member 11 made of a magnetic material moves in either direction by supplying and discharging the pressurized fluid to and from the internal cavities 6a and 6b, an induced power corresponding to the displacement amount of the guide member 11 is generated in the coil 16. And is applied to the output means via the lead wire 17. Therefore, appropriate processing such as amplification is performed, and the result is displayed on the display unit (not shown) of the display means.

It should be noted that the present invention is not limited to these embodiments, and various modifications can be made. If necessary, an O-ring is provided in the guide ring to more reliably seal the space between the guide member and the guide ring. Alternatively, in order to detect the relative displacement between the driven member and the guide ring, a detection means such as a non-contact potentiometer or a linear encoder can be used, and various modifications can be made within the scope of the claims. is there.

(Effects of the Invention) As described above in detail, the pneumatic actuator of the present invention is an air bag type pneumatic actuator that expands and deforms by the supply and discharge of a pressurized fluid to generate a contracting force in the axial direction. The problems of known air bag type actuators can be solved without compromising the advantages. That is, (i) By providing the guide member, the contraction force per pitch of the braided reinforcing structure is increased by (cross-sectional area of the guide member) × (applied control pressure). Further, (ii) since the amount of air consumed is reduced by the volume of the guide member, the operating pressure source such as the air compressor can be made compact.

Further, here, when the guide ring and the driven member are integrally formed, the assembling work of the actuator can be facilitated.

Further, when the means for detecting the relative displacement of the guide ring with respect to the guide member and the means for displaying the detection result are provided, the operating state of the actuator and the operating accuracy can be confirmed simply and quickly, and the driven It is possible to easily perform feedback control on the displacement amount of the member.

[Brief description of drawings]

FIG. 1 (a) is a plan view showing the pneumatic actuator of the present invention in a partial cross section, and FIG. 1 (b) is an explanatory view showing the operating condition of the actuator shown in FIG. 1 (a). 2 (a) and 2 (b) are explanatory views showing the operating principle of the actuator shown in FIG. 1, FIG. 3 is a partial cross-sectional view showing another embodiment of the present invention as a partial cross-section, and FIG. FIG. 5 is an explanatory view showing another embodiment of the present invention in section, and FIGS. 5 (a) and 5 (b) are partially sectional front views showing a known actuator and a reciprocating device using the known actuator. FIG. 1 ... Tubular body, 2 ... Braided reinforcing structure 3 ... Closing member, 4 ... Connection hole, 5 ... Fitting, 6 ... Internal cavity, 7 ... Connection pin hole, 8 ... Caulking cap, 9 ... Driven Member, 9a ...... Driven member main body 10 ...... Guide member, 11 ...... Guide ring 11a ...... Guide ring part, 12 ...... Contact part 14a, 14b ...... Communication hole, 15 ...... Crimping ring 16 ...... Coil , 17 ... Lead wire 18 ... Display means

Claims (3)

[Claims] 1. A tubular body (1) made of rubber or a rubber-like elastic material is entirely covered on the outside of the tubular body (1).
A braided reinforcing structure (2) of organic or inorganic high-strength fibers is arranged, and the openings of both ends of the tubular body (1) and the braided reinforcing structure (2) are sealed and joined by closing members (3a, 3b). , Defining a closed space inside the tubular body (1), and in the closed space,
A guide member (10) is provided so as to extend between the both closing members, and is fitted to the outer periphery of the guide member (10) so as to be displaceable in the axial direction of the guide member (10) to form the closed space into two internal cavities. The guide ring (11) to be divided is fixed to the inner peripheral surface of the tubular body (1), and at the radially outer position of the guide ring (11),
A driven member (9) holding the tubular body (1) and the braided reinforcing structure (2) is displaced outside the tubular body (1) and the braided reinforcing structure (2) integrally with the guide ring (11). Pneumatic, which is provided so that each of the closing members (3a, 3b) is provided with a supply / discharge port for supplying / discharging the pressurized fluid to / from the internal cavity.
Actuator. 2. The pneumatic actuator according to claim 1, wherein the guide ring (11) and the driven member (9) are integrally formed. 3. A tubular body (1) made of rubber or a rubber-like elastic material, which entirely covers the tubular body (1) outside the tubular body (1).
A braided reinforcing structure (2) of organic or inorganic high-strength fibers is arranged, and the openings of both ends of the tubular body (1) and the braided reinforcing structure (2) are sealed and joined by closing members (3a, 3b). , Defining a closed space inside the tubular body (1), and in the closed space,
A guide member (10) is provided so as to extend between the both closing members, and is fitted to the outer periphery of the guide member (10) so as to be displaceable in the axial direction of the guide member (10) to form the closed space into two internal cavities. The guide ring (11) to be divided is fixed to the inner peripheral surface of the tubular body (1), and at the radially outer position of the guide ring (11),
A driven member (9) holding the tubular body (1) and the braided reinforcing structure (2) is displaced outside the tubular body (1) and the braided reinforcing structure (2) integrally with the guide ring (11). The guide ring (11) is provided relative to the guide member (10) in such a manner that each of the closing members (3a, 3b) is provided with a supply / discharge port for supplying / discharging a pressurized fluid to / from the internal cavity. A pneumatic actuator comprising a detection means (16) for detecting a displacement amount and a display means (18) for displaying a relative displacement amount corresponding to an output signal from the detection means (16).